ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 10, pp. 1650−1655. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © V.K. Varentsov, V.I. Varentsova,
2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 10, pp. 1467−1472.
AND CORROSION PROTECTION OF METALS
Electrochemical Modiﬁ cation of a Nonwoven Fibrous Carbon
Material in Sulfuric Acid Solution
V. K. Varentsov and V. I. Varentsova
Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences,
ul. Kutateladze 18, Novosibirsk, 630128 Russia
Received August 30, 2015
Abstract—The inﬂ uence exerted by the electrode polarization of ANM nonwoven ﬁ brous carbon material in
0.25 M sulfuric acid solution on the pore composition and size, ﬁ ber surface morphology, elemental composition
of ﬁ bers, quantitative and qualitative composition of surface groups, stationary electrode potential, and electro-
chemical capacity was examined. These properties depend on the ratio of the cathodic and anodic constituents
of the current density (measured per geometric surface area).
Fibrous carbon materials (FCMs) are promising
materials exhibiting high reaction surface and high
chemical durability in aggressive media. They can be
used both independently as electrode materials and
as components of catalytically active and composite
materials containing, along with FCMs, also polymeric
materials, metals, or their compounds .
One of important problems in the development
of electrode and composite materials based on FCMs
is modiﬁ cation of the surface of the constituent ﬁ bers
to enhance their adhesion properties. Various methods
(usually chemical or thermal) enhancing the lyophilic
properties of the surface of carbon materials are used
for this purpose.
Electrochemical method shows promise for
modiﬁ cation of the surface of carbon materials [2–8].
Electrochemical methods are environmentally safer
and allow better control of the process by choosing the
medium in which the FCM modiﬁ cation is performed
and the electrolysis conditions.
As shown by Weinberg and Reddy , the properties
of the surface of carbon ﬁ bers subjected to anodic and
chemical treatment are identical. On the contrary, Janna-
koudakis et al.  found that the amount of phenol groups
participating in esteriﬁ cation on the surface of anodically
oxidized ﬁ bers is considerably larger than that on the sur-
face of chemically and thermally oxidized ﬁ bers.
Small diameter of FCM ﬁ bers (5–15 μm) and
the presence of internal porous structure in some
materials ensure high reactivity of these materials in
electrochemical processes. Therefore, electrochemical
treatment should lead not only to modiﬁ cation of the
external surface of FCM ﬁ bers, but also to changes in
their bulk properties. Changes in the surface and bulk
properties of FCMs, in turn, should lead to changes
in their physicochemical properties, including surface
tension, and hence in the adhesion properties.
The efﬁ ciency of using carbon materials, including
ﬁ brous carbon materials, is associated with the presence
of micro- and mesopores, and also of oxygen compounds
on their surface. For example, as shown by Mayer et al.
, operation of a two-layer electrochemical capacitor
is determined by pores whose effective diameter is
comparable with the thickness of the electrical double
layer (EDL) and is 2–4 nm. The major contribution to
the EDL capacity is made by the surface of FCM internal
pores . The access to internal mesopores is provided
by external macropores.
In this study, we examined the inﬂ uence exerted by
the conditions of electrode polarization (cathodic and/